shallow.con commit Merge branch 'dl/rebase-i-keep-base' (640f9cd)
   1#include "cache.h"
   2#include "repository.h"
   3#include "tempfile.h"
   4#include "lockfile.h"
   5#include "object-store.h"
   6#include "commit.h"
   7#include "tag.h"
   8#include "pkt-line.h"
   9#include "remote.h"
  10#include "refs.h"
  11#include "sha1-array.h"
  12#include "diff.h"
  13#include "revision.h"
  14#include "commit-slab.h"
  15#include "revision.h"
  16#include "list-objects.h"
  17#include "commit-slab.h"
  18#include "repository.h"
  19#include "commit-reach.h"
  20
  21void set_alternate_shallow_file(struct repository *r, const char *path, int override)
  22{
  23        if (r->parsed_objects->is_shallow != -1)
  24                BUG("is_repository_shallow must not be called before set_alternate_shallow_file");
  25        if (r->parsed_objects->alternate_shallow_file && !override)
  26                return;
  27        free(r->parsed_objects->alternate_shallow_file);
  28        r->parsed_objects->alternate_shallow_file = xstrdup_or_null(path);
  29}
  30
  31int register_shallow(struct repository *r, const struct object_id *oid)
  32{
  33        struct commit_graft *graft =
  34                xmalloc(sizeof(struct commit_graft));
  35        struct commit *commit = lookup_commit(the_repository, oid);
  36
  37        oidcpy(&graft->oid, oid);
  38        graft->nr_parent = -1;
  39        if (commit && commit->object.parsed)
  40                commit->parents = NULL;
  41        return register_commit_graft(r, graft, 0);
  42}
  43
  44int is_repository_shallow(struct repository *r)
  45{
  46        /*
  47         * NEEDSWORK: This function updates
  48         * r->parsed_objects->{is_shallow,shallow_stat} as a side effect but
  49         * there is no corresponding function to clear them when the shallow
  50         * file is updated.
  51         */
  52
  53        FILE *fp;
  54        char buf[1024];
  55        const char *path = r->parsed_objects->alternate_shallow_file;
  56
  57        if (r->parsed_objects->is_shallow >= 0)
  58                return r->parsed_objects->is_shallow;
  59
  60        if (!path)
  61                path = git_path_shallow(r);
  62        /*
  63         * fetch-pack sets '--shallow-file ""' as an indicator that no
  64         * shallow file should be used. We could just open it and it
  65         * will likely fail. But let's do an explicit check instead.
  66         */
  67        if (!*path || (fp = fopen(path, "r")) == NULL) {
  68                stat_validity_clear(r->parsed_objects->shallow_stat);
  69                r->parsed_objects->is_shallow = 0;
  70                return r->parsed_objects->is_shallow;
  71        }
  72        stat_validity_update(r->parsed_objects->shallow_stat, fileno(fp));
  73        r->parsed_objects->is_shallow = 1;
  74
  75        while (fgets(buf, sizeof(buf), fp)) {
  76                struct object_id oid;
  77                if (get_oid_hex(buf, &oid))
  78                        die("bad shallow line: %s", buf);
  79                register_shallow(r, &oid);
  80        }
  81        fclose(fp);
  82        return r->parsed_objects->is_shallow;
  83}
  84
  85/*
  86 * TODO: use "int" elemtype instead of "int *" when/if commit-slab
  87 * supports a "valid" flag.
  88 */
  89define_commit_slab(commit_depth, int *);
  90struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  91                int shallow_flag, int not_shallow_flag)
  92{
  93        int i = 0, cur_depth = 0;
  94        struct commit_list *result = NULL;
  95        struct object_array stack = OBJECT_ARRAY_INIT;
  96        struct commit *commit = NULL;
  97        struct commit_graft *graft;
  98        struct commit_depth depths;
  99
 100        init_commit_depth(&depths);
 101        while (commit || i < heads->nr || stack.nr) {
 102                struct commit_list *p;
 103                if (!commit) {
 104                        if (i < heads->nr) {
 105                                int **depth_slot;
 106                                commit = (struct commit *)
 107                                        deref_tag(the_repository,
 108                                                  heads->objects[i++].item,
 109                                                  NULL, 0);
 110                                if (!commit || commit->object.type != OBJ_COMMIT) {
 111                                        commit = NULL;
 112                                        continue;
 113                                }
 114                                depth_slot = commit_depth_at(&depths, commit);
 115                                if (!*depth_slot)
 116                                        *depth_slot = xmalloc(sizeof(int));
 117                                **depth_slot = 0;
 118                                cur_depth = 0;
 119                        } else {
 120                                commit = (struct commit *)
 121                                        object_array_pop(&stack);
 122                                cur_depth = **commit_depth_at(&depths, commit);
 123                        }
 124                }
 125                parse_commit_or_die(commit);
 126                cur_depth++;
 127                if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
 128                    (is_repository_shallow(the_repository) && !commit->parents &&
 129                     (graft = lookup_commit_graft(the_repository, &commit->object.oid)) != NULL &&
 130                     graft->nr_parent < 0)) {
 131                        commit_list_insert(commit, &result);
 132                        commit->object.flags |= shallow_flag;
 133                        commit = NULL;
 134                        continue;
 135                }
 136                commit->object.flags |= not_shallow_flag;
 137                for (p = commit->parents, commit = NULL; p; p = p->next) {
 138                        int **depth_slot = commit_depth_at(&depths, p->item);
 139                        if (!*depth_slot) {
 140                                *depth_slot = xmalloc(sizeof(int));
 141                                **depth_slot = cur_depth;
 142                        } else {
 143                                if (cur_depth >= **depth_slot)
 144                                        continue;
 145                                **depth_slot = cur_depth;
 146                        }
 147                        if (p->next)
 148                                add_object_array(&p->item->object,
 149                                                NULL, &stack);
 150                        else {
 151                                commit = p->item;
 152                                cur_depth = **commit_depth_at(&depths, commit);
 153                        }
 154                }
 155        }
 156        for (i = 0; i < depths.slab_count; i++) {
 157                int j;
 158
 159                for (j = 0; j < depths.slab_size; j++)
 160                        free(depths.slab[i][j]);
 161        }
 162        clear_commit_depth(&depths);
 163
 164        return result;
 165}
 166
 167static void show_commit(struct commit *commit, void *data)
 168{
 169        commit_list_insert(commit, data);
 170}
 171
 172/*
 173 * Given rev-list arguments, run rev-list. All reachable commits
 174 * except border ones are marked with not_shallow_flag. Border commits
 175 * are marked with shallow_flag. The list of border/shallow commits
 176 * are also returned.
 177 */
 178struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
 179                                                    int shallow_flag,
 180                                                    int not_shallow_flag)
 181{
 182        struct commit_list *result = NULL, *p;
 183        struct commit_list *not_shallow_list = NULL;
 184        struct rev_info revs;
 185        int both_flags = shallow_flag | not_shallow_flag;
 186
 187        /*
 188         * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
 189         * set at this point. But better be safe than sorry.
 190         */
 191        clear_object_flags(both_flags);
 192
 193        is_repository_shallow(the_repository); /* make sure shallows are read */
 194
 195        repo_init_revisions(the_repository, &revs, NULL);
 196        save_commit_buffer = 0;
 197        setup_revisions(ac, av, &revs, NULL);
 198
 199        if (prepare_revision_walk(&revs))
 200                die("revision walk setup failed");
 201        traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
 202
 203        if (!not_shallow_list)
 204                die("no commits selected for shallow requests");
 205
 206        /* Mark all reachable commits as NOT_SHALLOW */
 207        for (p = not_shallow_list; p; p = p->next)
 208                p->item->object.flags |= not_shallow_flag;
 209
 210        /*
 211         * mark border commits SHALLOW + NOT_SHALLOW.
 212         * We cannot clear NOT_SHALLOW right now. Imagine border
 213         * commit A is processed first, then commit B, whose parent is
 214         * A, later. If NOT_SHALLOW on A is cleared at step 1, B
 215         * itself is considered border at step 2, which is incorrect.
 216         */
 217        for (p = not_shallow_list; p; p = p->next) {
 218                struct commit *c = p->item;
 219                struct commit_list *parent;
 220
 221                if (parse_commit(c))
 222                        die("unable to parse commit %s",
 223                            oid_to_hex(&c->object.oid));
 224
 225                for (parent = c->parents; parent; parent = parent->next)
 226                        if (!(parent->item->object.flags & not_shallow_flag)) {
 227                                c->object.flags |= shallow_flag;
 228                                commit_list_insert(c, &result);
 229                                break;
 230                        }
 231        }
 232        free_commit_list(not_shallow_list);
 233
 234        /*
 235         * Now we can clean up NOT_SHALLOW on border commits. Having
 236         * both flags set can confuse the caller.
 237         */
 238        for (p = result; p; p = p->next) {
 239                struct object *o = &p->item->object;
 240                if ((o->flags & both_flags) == both_flags)
 241                        o->flags &= ~not_shallow_flag;
 242        }
 243        return result;
 244}
 245
 246static void check_shallow_file_for_update(struct repository *r)
 247{
 248        if (r->parsed_objects->is_shallow == -1)
 249                BUG("shallow must be initialized by now");
 250
 251        if (!stat_validity_check(r->parsed_objects->shallow_stat,
 252                                 git_path_shallow(r)))
 253                die("shallow file has changed since we read it");
 254}
 255
 256#define SEEN_ONLY 1
 257#define VERBOSE   2
 258#define QUICK 4
 259
 260struct write_shallow_data {
 261        struct strbuf *out;
 262        int use_pack_protocol;
 263        int count;
 264        unsigned flags;
 265};
 266
 267static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 268{
 269        struct write_shallow_data *data = cb_data;
 270        const char *hex = oid_to_hex(&graft->oid);
 271        if (graft->nr_parent != -1)
 272                return 0;
 273        if (data->flags & QUICK) {
 274                if (!has_object_file(&graft->oid))
 275                        return 0;
 276        } else if (data->flags & SEEN_ONLY) {
 277                struct commit *c = lookup_commit(the_repository, &graft->oid);
 278                if (!c || !(c->object.flags & SEEN)) {
 279                        if (data->flags & VERBOSE)
 280                                printf("Removing %s from .git/shallow\n",
 281                                       oid_to_hex(&c->object.oid));
 282                        return 0;
 283                }
 284        }
 285        data->count++;
 286        if (data->use_pack_protocol)
 287                packet_buf_write(data->out, "shallow %s", hex);
 288        else {
 289                strbuf_addstr(data->out, hex);
 290                strbuf_addch(data->out, '\n');
 291        }
 292        return 0;
 293}
 294
 295static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
 296                                   const struct oid_array *extra,
 297                                   unsigned flags)
 298{
 299        struct write_shallow_data data;
 300        int i;
 301        data.out = out;
 302        data.use_pack_protocol = use_pack_protocol;
 303        data.count = 0;
 304        data.flags = flags;
 305        for_each_commit_graft(write_one_shallow, &data);
 306        if (!extra)
 307                return data.count;
 308        for (i = 0; i < extra->nr; i++) {
 309                strbuf_addstr(out, oid_to_hex(extra->oid + i));
 310                strbuf_addch(out, '\n');
 311                data.count++;
 312        }
 313        return data.count;
 314}
 315
 316int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 317                          const struct oid_array *extra)
 318{
 319        return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
 320}
 321
 322const char *setup_temporary_shallow(const struct oid_array *extra)
 323{
 324        struct tempfile *temp;
 325        struct strbuf sb = STRBUF_INIT;
 326
 327        if (write_shallow_commits(&sb, 0, extra)) {
 328                temp = xmks_tempfile(git_path("shallow_XXXXXX"));
 329
 330                if (write_in_full(temp->fd, sb.buf, sb.len) < 0 ||
 331                    close_tempfile_gently(temp) < 0)
 332                        die_errno("failed to write to %s",
 333                                  get_tempfile_path(temp));
 334                strbuf_release(&sb);
 335                return get_tempfile_path(temp);
 336        }
 337        /*
 338         * is_repository_shallow() sees empty string as "no shallow
 339         * file".
 340         */
 341        return "";
 342}
 343
 344void setup_alternate_shallow(struct lock_file *shallow_lock,
 345                             const char **alternate_shallow_file,
 346                             const struct oid_array *extra)
 347{
 348        struct strbuf sb = STRBUF_INIT;
 349        int fd;
 350
 351        fd = hold_lock_file_for_update(shallow_lock,
 352                                       git_path_shallow(the_repository),
 353                                       LOCK_DIE_ON_ERROR);
 354        check_shallow_file_for_update(the_repository);
 355        if (write_shallow_commits(&sb, 0, extra)) {
 356                if (write_in_full(fd, sb.buf, sb.len) < 0)
 357                        die_errno("failed to write to %s",
 358                                  get_lock_file_path(shallow_lock));
 359                *alternate_shallow_file = get_lock_file_path(shallow_lock);
 360        } else
 361                /*
 362                 * is_repository_shallow() sees empty string as "no
 363                 * shallow file".
 364                 */
 365                *alternate_shallow_file = "";
 366        strbuf_release(&sb);
 367}
 368
 369static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 370{
 371        int fd = *(int *)cb;
 372        if (graft->nr_parent == -1)
 373                packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
 374        return 0;
 375}
 376
 377void advertise_shallow_grafts(int fd)
 378{
 379        if (!is_repository_shallow(the_repository))
 380                return;
 381        for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
 382}
 383
 384/*
 385 * mark_reachable_objects() should have been run prior to this and all
 386 * reachable commits marked as "SEEN", except when quick_prune is non-zero,
 387 * in which case lines are excised from the shallow file if they refer to
 388 * commits that do not exist (any longer).
 389 */
 390void prune_shallow(unsigned options)
 391{
 392        struct lock_file shallow_lock = LOCK_INIT;
 393        struct strbuf sb = STRBUF_INIT;
 394        unsigned flags = SEEN_ONLY;
 395        int fd;
 396
 397        if (options & PRUNE_QUICK)
 398                flags |= QUICK;
 399
 400        if (options & PRUNE_SHOW_ONLY) {
 401                flags |= VERBOSE;
 402                write_shallow_commits_1(&sb, 0, NULL, flags);
 403                strbuf_release(&sb);
 404                return;
 405        }
 406        fd = hold_lock_file_for_update(&shallow_lock,
 407                                       git_path_shallow(the_repository),
 408                                       LOCK_DIE_ON_ERROR);
 409        check_shallow_file_for_update(the_repository);
 410        if (write_shallow_commits_1(&sb, 0, NULL, flags)) {
 411                if (write_in_full(fd, sb.buf, sb.len) < 0)
 412                        die_errno("failed to write to %s",
 413                                  get_lock_file_path(&shallow_lock));
 414                commit_lock_file(&shallow_lock);
 415        } else {
 416                unlink(git_path_shallow(the_repository));
 417                rollback_lock_file(&shallow_lock);
 418        }
 419        strbuf_release(&sb);
 420}
 421
 422struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
 423
 424/*
 425 * Step 1, split sender shallow commits into "ours" and "theirs"
 426 * Step 2, clean "ours" based on .git/shallow
 427 */
 428void prepare_shallow_info(struct shallow_info *info, struct oid_array *sa)
 429{
 430        int i;
 431        trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
 432        memset(info, 0, sizeof(*info));
 433        info->shallow = sa;
 434        if (!sa)
 435                return;
 436        ALLOC_ARRAY(info->ours, sa->nr);
 437        ALLOC_ARRAY(info->theirs, sa->nr);
 438        for (i = 0; i < sa->nr; i++) {
 439                if (has_object_file(sa->oid + i)) {
 440                        struct commit_graft *graft;
 441                        graft = lookup_commit_graft(the_repository,
 442                                                    &sa->oid[i]);
 443                        if (graft && graft->nr_parent < 0)
 444                                continue;
 445                        info->ours[info->nr_ours++] = i;
 446                } else
 447                        info->theirs[info->nr_theirs++] = i;
 448        }
 449}
 450
 451void clear_shallow_info(struct shallow_info *info)
 452{
 453        free(info->ours);
 454        free(info->theirs);
 455}
 456
 457/* Step 4, remove non-existent ones in "theirs" after getting the pack */
 458
 459void remove_nonexistent_theirs_shallow(struct shallow_info *info)
 460{
 461        struct object_id *oid = info->shallow->oid;
 462        int i, dst;
 463        trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
 464        for (i = dst = 0; i < info->nr_theirs; i++) {
 465                if (i != dst)
 466                        info->theirs[dst] = info->theirs[i];
 467                if (has_object_file(oid + info->theirs[i]))
 468                        dst++;
 469        }
 470        info->nr_theirs = dst;
 471}
 472
 473define_commit_slab(ref_bitmap, uint32_t *);
 474
 475#define POOL_SIZE (512 * 1024)
 476
 477struct paint_info {
 478        struct ref_bitmap ref_bitmap;
 479        unsigned nr_bits;
 480        char **pools;
 481        char *free, *end;
 482        unsigned pool_count;
 483};
 484
 485static uint32_t *paint_alloc(struct paint_info *info)
 486{
 487        unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
 488        unsigned size = nr * sizeof(uint32_t);
 489        void *p;
 490        if (!info->pool_count || size > info->end - info->free) {
 491                if (size > POOL_SIZE)
 492                        BUG("pool size too small for %d in paint_alloc()",
 493                            size);
 494                info->pool_count++;
 495                REALLOC_ARRAY(info->pools, info->pool_count);
 496                info->free = xmalloc(POOL_SIZE);
 497                info->pools[info->pool_count - 1] = info->free;
 498                info->end = info->free + POOL_SIZE;
 499        }
 500        p = info->free;
 501        info->free += size;
 502        return p;
 503}
 504
 505/*
 506 * Given a commit SHA-1, walk down to parents until either SEEN,
 507 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
 508 * all walked commits.
 509 */
 510static void paint_down(struct paint_info *info, const struct object_id *oid,
 511                       unsigned int id)
 512{
 513        unsigned int i, nr;
 514        struct commit_list *head = NULL;
 515        int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
 516        size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
 517        struct commit *c = lookup_commit_reference_gently(the_repository, oid,
 518                                                          1);
 519        uint32_t *tmp; /* to be freed before return */
 520        uint32_t *bitmap;
 521
 522        if (!c)
 523                return;
 524
 525        tmp = xmalloc(bitmap_size);
 526        bitmap = paint_alloc(info);
 527        memset(bitmap, 0, bitmap_size);
 528        bitmap[id / 32] |= (1U << (id % 32));
 529        commit_list_insert(c, &head);
 530        while (head) {
 531                struct commit_list *p;
 532                struct commit *c = pop_commit(&head);
 533                uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
 534
 535                /* XXX check "UNINTERESTING" from pack bitmaps if available */
 536                if (c->object.flags & (SEEN | UNINTERESTING))
 537                        continue;
 538                else
 539                        c->object.flags |= SEEN;
 540
 541                if (*refs == NULL)
 542                        *refs = bitmap;
 543                else {
 544                        memcpy(tmp, *refs, bitmap_size);
 545                        for (i = 0; i < bitmap_nr; i++)
 546                                tmp[i] |= bitmap[i];
 547                        if (memcmp(tmp, *refs, bitmap_size)) {
 548                                *refs = paint_alloc(info);
 549                                memcpy(*refs, tmp, bitmap_size);
 550                        }
 551                }
 552
 553                if (c->object.flags & BOTTOM)
 554                        continue;
 555
 556                if (parse_commit(c))
 557                        die("unable to parse commit %s",
 558                            oid_to_hex(&c->object.oid));
 559
 560                for (p = c->parents; p; p = p->next) {
 561                        if (p->item->object.flags & SEEN)
 562                                continue;
 563                        commit_list_insert(p->item, &head);
 564                }
 565        }
 566
 567        nr = get_max_object_index();
 568        for (i = 0; i < nr; i++) {
 569                struct object *o = get_indexed_object(i);
 570                if (o && o->type == OBJ_COMMIT)
 571                        o->flags &= ~SEEN;
 572        }
 573
 574        free(tmp);
 575}
 576
 577static int mark_uninteresting(const char *refname, const struct object_id *oid,
 578                              int flags, void *cb_data)
 579{
 580        struct commit *commit = lookup_commit_reference_gently(the_repository,
 581                                                               oid, 1);
 582        if (!commit)
 583                return 0;
 584        commit->object.flags |= UNINTERESTING;
 585        mark_parents_uninteresting(commit);
 586        return 0;
 587}
 588
 589static void post_assign_shallow(struct shallow_info *info,
 590                                struct ref_bitmap *ref_bitmap,
 591                                int *ref_status);
 592/*
 593 * Step 6(+7), associate shallow commits with new refs
 594 *
 595 * info->ref must be initialized before calling this function.
 596 *
 597 * If used is not NULL, it's an array of info->shallow->nr
 598 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
 599 * m-th shallow commit from info->shallow.
 600 *
 601 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
 602 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
 603 * the ref needs some shallow commits from either info->ours or
 604 * info->theirs.
 605 */
 606void assign_shallow_commits_to_refs(struct shallow_info *info,
 607                                    uint32_t **used, int *ref_status)
 608{
 609        struct object_id *oid = info->shallow->oid;
 610        struct oid_array *ref = info->ref;
 611        unsigned int i, nr;
 612        int *shallow, nr_shallow = 0;
 613        struct paint_info pi;
 614
 615        trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
 616        ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
 617        for (i = 0; i < info->nr_ours; i++)
 618                shallow[nr_shallow++] = info->ours[i];
 619        for (i = 0; i < info->nr_theirs; i++)
 620                shallow[nr_shallow++] = info->theirs[i];
 621
 622        /*
 623         * Prepare the commit graph to track what refs can reach what
 624         * (new) shallow commits.
 625         */
 626        nr = get_max_object_index();
 627        for (i = 0; i < nr; i++) {
 628                struct object *o = get_indexed_object(i);
 629                if (!o || o->type != OBJ_COMMIT)
 630                        continue;
 631
 632                o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
 633        }
 634
 635        memset(&pi, 0, sizeof(pi));
 636        init_ref_bitmap(&pi.ref_bitmap);
 637        pi.nr_bits = ref->nr;
 638
 639        /*
 640         * "--not --all" to cut short the traversal if new refs
 641         * connect to old refs. If not (e.g. force ref updates) it'll
 642         * have to go down to the current shallow commits.
 643         */
 644        head_ref(mark_uninteresting, NULL);
 645        for_each_ref(mark_uninteresting, NULL);
 646
 647        /* Mark potential bottoms so we won't go out of bound */
 648        for (i = 0; i < nr_shallow; i++) {
 649                struct commit *c = lookup_commit(the_repository,
 650                                                 &oid[shallow[i]]);
 651                c->object.flags |= BOTTOM;
 652        }
 653
 654        for (i = 0; i < ref->nr; i++)
 655                paint_down(&pi, ref->oid + i, i);
 656
 657        if (used) {
 658                int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
 659                memset(used, 0, sizeof(*used) * info->shallow->nr);
 660                for (i = 0; i < nr_shallow; i++) {
 661                        const struct commit *c = lookup_commit(the_repository,
 662                                                               &oid[shallow[i]]);
 663                        uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
 664                        if (*map)
 665                                used[shallow[i]] = xmemdupz(*map, bitmap_size);
 666                }
 667                /*
 668                 * unreachable shallow commits are not removed from
 669                 * "ours" and "theirs". The user is supposed to run
 670                 * step 7 on every ref separately and not trust "ours"
 671                 * and "theirs" any more.
 672                 */
 673        } else
 674                post_assign_shallow(info, &pi.ref_bitmap, ref_status);
 675
 676        clear_ref_bitmap(&pi.ref_bitmap);
 677        for (i = 0; i < pi.pool_count; i++)
 678                free(pi.pools[i]);
 679        free(pi.pools);
 680        free(shallow);
 681}
 682
 683struct commit_array {
 684        struct commit **commits;
 685        int nr, alloc;
 686};
 687
 688static int add_ref(const char *refname, const struct object_id *oid,
 689                   int flags, void *cb_data)
 690{
 691        struct commit_array *ca = cb_data;
 692        ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
 693        ca->commits[ca->nr] = lookup_commit_reference_gently(the_repository,
 694                                                             oid, 1);
 695        if (ca->commits[ca->nr])
 696                ca->nr++;
 697        return 0;
 698}
 699
 700static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
 701{
 702        unsigned int i;
 703        if (!ref_status)
 704                return;
 705        for (i = 0; i < nr; i++)
 706                if (bitmap[i / 32] & (1U << (i % 32)))
 707                        ref_status[i]++;
 708}
 709
 710/*
 711 * Step 7, reachability test on "ours" at commit level
 712 */
 713static void post_assign_shallow(struct shallow_info *info,
 714                                struct ref_bitmap *ref_bitmap,
 715                                int *ref_status)
 716{
 717        struct object_id *oid = info->shallow->oid;
 718        struct commit *c;
 719        uint32_t **bitmap;
 720        int dst, i, j;
 721        int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
 722        struct commit_array ca;
 723
 724        trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
 725        if (ref_status)
 726                memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
 727
 728        /* Remove unreachable shallow commits from "theirs" */
 729        for (i = dst = 0; i < info->nr_theirs; i++) {
 730                if (i != dst)
 731                        info->theirs[dst] = info->theirs[i];
 732                c = lookup_commit(the_repository, &oid[info->theirs[i]]);
 733                bitmap = ref_bitmap_at(ref_bitmap, c);
 734                if (!*bitmap)
 735                        continue;
 736                for (j = 0; j < bitmap_nr; j++)
 737                        if (bitmap[0][j]) {
 738                                update_refstatus(ref_status, info->ref->nr, *bitmap);
 739                                dst++;
 740                                break;
 741                        }
 742        }
 743        info->nr_theirs = dst;
 744
 745        memset(&ca, 0, sizeof(ca));
 746        head_ref(add_ref, &ca);
 747        for_each_ref(add_ref, &ca);
 748
 749        /* Remove unreachable shallow commits from "ours" */
 750        for (i = dst = 0; i < info->nr_ours; i++) {
 751                if (i != dst)
 752                        info->ours[dst] = info->ours[i];
 753                c = lookup_commit(the_repository, &oid[info->ours[i]]);
 754                bitmap = ref_bitmap_at(ref_bitmap, c);
 755                if (!*bitmap)
 756                        continue;
 757                for (j = 0; j < bitmap_nr; j++)
 758                        if (bitmap[0][j] &&
 759                            /* Step 7, reachability test at commit level */
 760                            !in_merge_bases_many(c, ca.nr, ca.commits)) {
 761                                update_refstatus(ref_status, info->ref->nr, *bitmap);
 762                                dst++;
 763                                break;
 764                        }
 765        }
 766        info->nr_ours = dst;
 767
 768        free(ca.commits);
 769}
 770
 771/* (Delayed) step 7, reachability test at commit level */
 772int delayed_reachability_test(struct shallow_info *si, int c)
 773{
 774        if (si->need_reachability_test[c]) {
 775                struct commit *commit = lookup_commit(the_repository,
 776                                                      &si->shallow->oid[c]);
 777
 778                if (!si->commits) {
 779                        struct commit_array ca;
 780
 781                        memset(&ca, 0, sizeof(ca));
 782                        head_ref(add_ref, &ca);
 783                        for_each_ref(add_ref, &ca);
 784                        si->commits = ca.commits;
 785                        si->nr_commits = ca.nr;
 786                }
 787
 788                si->reachable[c] = in_merge_bases_many(commit,
 789                                                       si->nr_commits,
 790                                                       si->commits);
 791                si->need_reachability_test[c] = 0;
 792        }
 793        return si->reachable[c];
 794}